Reduced tillage strategies are popular in farming. Reduced tillage techniques include no tilling, strip tilling, mulch tilling, rotational tilling, and ridge tilling. Of these tillage techniques, strip tilling often referred to as “strip-till” is a conservation system that uses a minimum of tillage by focusing tillage actions on the intended seed bed or seed furrow while leaving the surrounding areas relatively undisturbed. Strip tilling combines the soil drying and warming benefits of conventional tillage with the soil-protecting advantages of no tilling at all by disturbing only the seed row portion of the soil. Another benefit of strip tilling is that a farmer can apply chemicals and fertilizer at the same time as tillage.
Some of the more immediate benefits of strip tilling include the field-wide preservation of soil colloids, soil pores, and root channels from previous crops, and strip tilling also preserve crop residue which aids in the buildup of soil organic matter. Additionally, the presence of large pores in the soil increases water percolation and improves crop rooting. Long-term research studies have shown that utilization of strip tilling and strategic fertilizer placement improves yield potential, including the preservation of water, soil, and improved plant health. Soils that were managed under strip tilling conditions generally have more beneficial worms per square foot, more frequent and larger soil pores per square inch, greater percent organic matter, faster water infiltration rates, and greater crop yields compared to soils that were managed under conventional-tillage. That is most likely the reason that strip tilling acreage in the Great Plains has greatly increased since the year 2000.
Strip tilling also has many economic benefits. Strip tillage reduces the amount of trips through a field to two or possibly even one when using a strip till implement combined with a planter. This can save the farmer a considerable amount of time and fuel, and it reduces soil compaction due to the press weight of tractors in a field. With the use of GPS guided tractors, precision farming can increase overall yields even more.
Strip tilling is also used effectively in the preparation of a field for planting in which cover crops have been planted. Cover crops are planted primarily to manage soil fertility, soil quality, water, weeds, pests, diseases, biodiversity and wildlife in agro-ecosystems, ecological systems managed and largely shaped by humans across a range of intensities to produce food, feed, or fiber. However, two primary uses of cover crops are emerging in the U.S. to augment farming strategies. First, cover crops are often used as an alternative to herbicide weed controls; and second cover crops are used for conservation, such as water and soil conservation.
In reduced tillage strategies, weed suppression can be problematic, and expensive. Fields left uncultivated tend to breed weeds and especially those weeds that have become resistance to herbicidal management which tend to proliferate in farming communities. Hence, reduced tilling may cause an increase in total farm expenses because herbicides are used in place of cultivation for weed suppression.
For example, weeds such as Morningglory, Pigweed (including Palmer amaranth), Lambsquarters, Marestail, Waterhemp, Giant and common ragweed, Velvetleaf, Eastern Black Nightshade, and Kochia are a prevalent and increasing problem in different parts of the country. Palmer amaranth (aka “Pigweed”—Amaranthus palmeri) is particularly relevant to the Southeast where it is a recurring problem for farmers there. Most of these varieties are becoming herbicide resistant, and farmers are seeking alternatives to herbicides to combat the invasion of these weeds. Therefore, farmers using reduced tillage methods are always looking for ways to combat the weed proliferation problem.
One alternative to herbicides is to use cover crops to cover the ground and crowd out weeds between primary crop growing seasons. A thick cover crop will compete well with weeds during the cover crop growth period, and can prevent most germinated weed seeds from completing their life cycle and reproducing. If the cover crop is left on the soil surface rather than incorporated into the soil as a green manure after its growth is terminated, it can form a nearly impenetrable mat. This drastically reduces light transmittance to weed seeds, which in many cases reduces weed seed germination rates. Furthermore, even when weed seeds germinate, they often run out of stored energy for growth before building the necessary structural capacity to break through the cover crop mulch layer, thereby smothering the weed seeds before maturing into a reproducing plant. Hence, cover crops are becoming a viable alternative to the use of ever increasing quantities of herbicides.
By reducing soil erosion, cover crops often also reduce both the rate and quantity of water that drains off the field, which would normally pose environmental risks to waterways and ecosystems downstream. Cover crop biomass acts as a physical barrier between rainfall and the soil surface, allowing raindrops to steadily trickle down through the soil profile. Also, as stated above, cover crop root growth results in the formation of soil pores, which in addition to enhancing soil macro-fauna habitat, and provides pathways for water to filter through the soil profile rather than draining off the field as surface flow. With increased water infiltration, the potential for soil water storage and the recharging of aquifers can be improved, as well as generally increasing the soil moisture content.
Cover crops also can conserve water in another manner. Just before cover crops are killed, such as by mowing, tilling, disc mulching, rolling, or a herbicide application, the cover crop plants contain large amounts of moisture. When the cover crop is incorporated into the soil, or left on the soil surface, it increases soil moisture. In addition, in agro-ecosystems where water for crop production is in short supply, cover crops can be used as a mulch to conserve water by shading and cooling the soil surface, thereby reducing the evaporation of soil moisture.
Although cover crops can perform multiple functions in an agro-ecosystem simultaneously, they are often grown for the sole purpose of preventing soil erosion. Soil erosion is a process that can irreparably reduce the productive capacity of an agro-ecosystem. However, dense cover crop stands physically slow down the velocity of rainfall before it contacts the soil surface, preventing soil splashing and erosive surface runoff, and cover crop root networks help anchor the soil in place and increase soil porosity, creating suitable habitat networks for soil macro-fauna.
However, while the use of cover crops in combination with strip tilling have significant advantages to increase crop yields and over-all economic advantages, cover crops must be tilled to some degree prior to primary crop planting. The use of strip tilling with cover crops is the optimal strategy, but using an optimal strip tilling procedure can be elusive, due to the dense foliage of cover crops and due to the strong network of roots developed by cover crops. This can require a farmer to make multiple tilling passes over a cover crop field to properly prepare the field for planting, thereby costing the farmer more in gas, time, and labor, and defeating the very purpose of strip tilling.
Therefore, what is needed is a farming implement to allow for the efficient preparation of a farm field having a cover crop just prior to primary crop planting process, while creating a superior seedbed.